Pdfmerger updated for python3 usage

README.md

This was originally taken from https://superuser.com/a/1012669/894282 and then updated to be compatible with python 3.X

Requires pypdf2 to be installed.

pdfmerger.py

#! /usr/bin/env python
# Original author Nicholas Kim, modified by Yan Pashkovsky
# New license - GPL v3
import sys
import time
from pathlib import Path
# from PyPDF2 import PdfReader, PdfWriter
# try:
#     from PyPDF2.utils import PdfReadError
# except ImportError:
#     from PyPDF2._reader import PdfReadError

from pypdf import PdfReader, PdfWriter
try:
    from pypdf.utils import PdfReadError
except ImportError:
    from pypdf._reader import PdfReadError

def eprint(*args, **kwargs):
    """Print to stderr

    Taken from https://stackoverflow.com/a/14981125/7564988
    """
    print(*args, file=sys.stderr, **kwargs)

def get_cmdline_arguments():
    """Retrieve command line arguments."""

    from optparse import OptionParser

    usage_string = "%prog [-v] [-o output_name] [-b bookmarks_file] file1, file2 [, ...]"

    parser = OptionParser(usage_string)
    parser.add_option(
        "-o", "--output",
        dest="output_filename",
        default=time.strftime("output_%Y%m%d_%H%M%S"),
        help="Specify output filename (exclude .pdf extension); default is current date/time stamp"
    )
    parser.add_option(
        "-b", "--bookmarks",
        dest="bookmark_file",
        default=None,
        help="Specify the bookmark names for each file. The file should be new-line delimited and the number of lies must match the number of input files. If not given, the name of each file will be used as the bookmark name."
    )
    parser.add_option("-v", "--verbose",
                  action="store_true", dest="verbose", default=True,
                  help="Print detailed output (undoes quiet)")
    parser.add_option("-q", "--quiet",
                  action="store_false", dest="verbose", default=True,
                  help="Do not print detailed output (undoes verbose)")

    options, args = parser.parse_args()
    if len(args) < 2:
        parser.print_help()
        sys.exit(1)
    return options, args

def main():
    options, filenames = get_cmdline_arguments()
    verboseprint = print if options.verbose else lambda *a, **k: None
    output_pdf_name = options.output_filename + ".pdf"
    files_to_merge = []
    bookmarks = []

    verboseprint(f"Output filename: {output_pdf_name}")
    verboseprint(f"Input filenames:")
    for f in filenames:
        verboseprint(f"\t{f}")

    # gather bookmark names
    if options.bookmark_file:
        bookmark_path = Path(options.bookmark_file)
        assert bookmark_path.exists(), f"Bookmark file '{options.bookmark_file}' does not exist."
        with bookmark_path.open() as file:
            bookmarks = file.read().splitlines()

        assert len(bookmarks) == len(filenames), f"Number of bookmarks in '{bookmark_path}' ({len(bookmarks)}) does not match the number of files ({len(filenames)})"

        verboseprint(f"Bookmark Names:")
        for b in bookmarks:
            verboseprint(f"\t{b}")
    else:
        bookmarks = [filename for filename in filenames]
        verboseprint(f"Bookmark Names: Same as filenames")

    # get PDF files
    for f in filenames:
        try:
            next_pdf_file = PdfReader(open(f, "rb"))
        except(PdfReadError):
            eprint("%s is not a valid PDF file." % f)
            sys.exit(1)
        except(IOError):
            eprint("%s could not be found." % f)
            sys.exit(1)
        else:
            files_to_merge.append(next_pdf_file)

    # merge page by page
    output_pdf_stream = PdfWriter()
    j=0
    k=0
    for f in files_to_merge:
        verboseprint(f"Adding {filenames[k]} to output")
        for i in range(len(f.pages)):
            output_pdf_stream.add_page(f.pages[i])
            if i==0:
                output_pdf_stream.add_outline_item(str(bookmarks[k]),j)
            j = j + 1
        k += 1

    # create output pdf file
    verboseprint(f"Writing output file...")
    try:
        output_pdf_file = open(output_pdf_name, "wb")
        output_pdf_stream.write(output_pdf_file)
    finally:
        output_pdf_file.close()

    print("%s successfully created." % output_pdf_name)


if __name__ == "__main__":
    main()

Latest update adds the ability to customize what the bookmark labels to be added are and also adds more verbose output (with the option of disabling).